A heat exchanger, which is an apparatus that absorbs heat from one side between two environments having a temperature difference and dissipates the absorbed heat to the other side, is operated as a cooling system when it absorbs inner heat and dissipates the absorbed heat to the outside, and is operated as a heating system when it absorbs outside heat and dissipates the absorbed heat to an inside.
FIGS. 1 to 3 are a perspective view, an exploded perspective view, and a schematic cross-sectional view illustrating a heat exchanger and a header tank according to the related art.
In general, the heat exchanger is configured to include a header 11 in which a plurality of tube insertion holes 11a arranged in a length direction of the header 11 is formed. A tank 12 is coupled to the header 11 to form a refrigerant fluid path in an inner space, and is configured to prevent leakage of a heat exchanging medium to the inside and the outside of a header tank 10 by a baffle 13 interposed and brazed between the header 11 and the tank 12.
Here, the header 11 having an end portion formed to be bent is configured so that an end portion of the tank 12 is seated on and coupled to an inner side of the end portion of the header 11, and the baffle 13 having an appearance formed to correspond to a shape of the inner space formed by the coupling of the header 11 and the tank 12 is coupled to the header 11. However, as illustrated in FIGS. 3 and 4, as a bent edge portion 11b of the end portion of the header 11 is formed in a round shape by a bending, an empty space is formed in a portion at which the header 11, the tank 12, and the baffle 13 are joined with one another. As a result, since a gap is not accurately filled at the time of brazing, there is a problem in that the heat exchanging medium is leaked through a bonded portion, thereby causing performance of the heat exchanger to be degraded. See also Korean Patent Document KR 2007-0081347 A (Date 2007 Aug. 16).